I was hoping some one might have ballistics info for the 30-248 wildcat cartridge? I tried asking on this this thread before but the conversation quickly turned to the subject of catting, and the thread got bumped to a location where I will never find ballistics info. that being said please don't respond with non ballistics related banter, so this thread wont get bumped. I have left the question intentionally vague for the stated reason, but I am looking primary for basic load, velocity, flight path type of stuff.
If any one can help it would be greatly appreciated.

CAUTION: This post discusses loads or load data that doesn't exist in tested published form. It is purely theoretical. Neither the writer, The Shooter's Forum, nor the staff of The Shooter's Forum assume any liability for damage or injury resulting from using this information.DO NOT ATTEMPT TO DUPLICATE THE DESCRIBED LOADS without first working them up from a published safe starting level charge while watching for pressure signs. If you don't know how to do that, don't try.

The problem for wildcats is no manufacturer has done pressure testing. So what I am about to say is all totally theoretical based on QuickLOAD calculations. Don't believe it without load workup.

It looks to me like this cartridge is intended to get full .30-06 velocity and at the same pressures in a .308 Win length cartridge using the same bullets and powders the .30-06 likes. Thus it will outperform the .308 by up to a couple hundred fps, depending on the load mix, but more often by more like 50-100 fps. It should allow for the heavier bullets that the .30-06 can work with that the .308 doesn't like.

QuickLOAD lists both .30-284 and .30/284 Win. The difference between them is small; about one grain more case water capacity for the latter and about 0.015" more case length and about 0.034" more COL. The former has the same length as a .308 Win; 2.800" max; the latter 2.834".

If I plug in some known maximum loads for the .30-06, then change only the case to the .30-284, I find that for 150 grain bullets I get very close peak pressure and muzzle velocity if I multiply the .30-06 powder charge by 0.95. For 180 grain bullets the multiplier was 0.925. You can extrapolate between weights for an approximation. Take your result, knock it down 10% and work up in 1% increments while watching for pressure signs. See if it holds up.

"First contemplation of the problems of Interior Ballistics gives the impression that they should yield rather easily to relatively simple methods of analysis. Further study shows the subject to be of almost unbelievable complexity." Homer Powley

QuickLOAD lists both .30-284 and .30/284 Win. The difference between them is small; about one grain more case water capacity for the latter and about 0.015" more case length and about 0.034" more COL. The former has the same length as a .308 Win; 2.800" max; the latter 2.834".

Out of curiosity, Nick, does QuickLOAD list anything for the Swiss GP 11 round? And if so, how close is it to their sample .30-284 and .30/284 Win. rounds?

If (as I suspect) they are all within a grain or so of water capacity, there should be large amounts of ballistic data readily available for the Swiss cartridge to help peder1979.

As there is only about one grain difference in case capacity between the 30-284 and the 30-06, I'd think that you'd have all the load data and ballistic info you'd ever want right there.

It's a 30-06 in everything but headstamp.

We tried to tell the OP that in the previous thread, but it turned into something more about wildcat cartridges and their relative merits. I guess he was hoping for explicit recipes to be used with this 'cat, but I'm just not sure many of those exist. Start at 90% of '06 loads and work up?

If the OP is anything like I was with my first wildcat, he might be over-thinking the challenge of creating safe handloads. Even the strangest 'cat is still just a metallic case, burning powder and spittin' bullets; the only mystery is in finding the case capacity and working pressure limits. With software like QuickLoad, finding a safe starting point is easier than ever and the indicators for whether or not a load is safe in your gun are the exact some ones you look for with a standard cartridge. Reloading is 90% science and the other half art, but there isn't anything overly nebulous about it.

Good call. You are correct that the 7.5×55 GP11 is another close one; the closest, except that its listed peak pressure is about 7% lower. QL gives the Swiss round 65 grain default case capacity. It gives the .30-284 66 grains; the .30/284 Win. gets 67 grains, and the .30-06 gets 68 grains. So, if you look up loads for the Swiss round it appears you could use them as listed, then work up about 4% higher to make the higher peak pressure in the slightly larger case. I would not skip the the starting loads, though. The .284 parent case has a rebated rim design, so its extra diameter should improve the burn efficiency a little bit and raise bolt thrust a little, and those are the only points of caution about simple substitution that need to be born in mind. The solution, though, is simple. Work up from starting loads watching for the usual pressure signs.

"First contemplation of the problems of Interior Ballistics gives the impression that they should yield rather easily to relatively simple methods of analysis. Further study shows the subject to be of almost unbelievable complexity." Homer Powley

My reasons for wildcatting outweigh any reasons for the existence of a new cartridge thats ballistically identical to something else. Its the desire to have something that I have personally created and used that is the basis behind my own creations. 30 X 284 has a good sound to it; I might be tempted to try it myself!

I hope I'm not out of line here and if I am, I apologize for it and just delete my post if you deem innapropriate...

I personally have built well over 50 rifles / handguns chambered for the 30-284 and in every single instance, starting loads were identical to that of the 30-06...

PRIMERS: stay with standard or Match primers - magnum primers are not needed or required...

BULLETS: this cartridge works well with any bullet weight from 110 gr. up to and including 200 grs....

POWDER: I have found powders like IMR-4350, IMR-4831, Reloader 22, Reloader 25 and Viht. N540 to provide the best performance from the 30-284...

VELOCITY: I have also found velocity from the 30-284 to be somewhat higher than that of the 30-06, even when identical powder charges are used. Like most things in life though, there are exceptions to the rule....

I was hoping some one might have ballistics info for the 30-248 wildcat cartridge? I tried asking on this this thread before but the conversation quickly turned to the subject of catting, and the thread got bumped to a location where I will never find ballistics info. that being said please don't respond with non ballistics related banter, so this thread wont get bumped. I have left the question intentionally vague for the stated reason, but I am looking primary for basic load, velocity, flight path type of stuff.
If any one can help it would be greatly appreciated.

One thing I've learned is never throw old reloading manual away.

Hodgdon Manual # 26 published 1992 has some interesting reloading data under the heading "30/06 & 30/284" and here what they print about the 30/284. "The 30/284 is simply a necked-up 284 Winchester case. This cartridge is the same ballistically as the 30/06 and uses the same data."
The also have data for the 6/284 with Pressure reading from start to max loads.

I would warn anyone about trying to interpolate these loads back to the old 30:06. It really depends, with any caliber above the 6x284, on how long the action is in the rifle being wildcatted. I had a .284 in a Win. M.88, and a 25-284 in a Mark X Mauser. There's a big difference in these two presentations. In the factory 284, lever action, the long bullets go deep into the belly of the case. In my Mark X Mauser, I could seat them out so they only went in to the base of the neck. The O.P. doesn't say what length of rifle action he's using, and that could boost pressures through the roof. In metrics, the .284 is a 55mm long case. The 308 Win. is only 51mm long. So if he uses the .284 case to magnumize a shorty action, he will find that he loses most of his increase, when using the longer .308 bullets. But, like Daylight Savings Time, he will "Spring Ahead", big time, using really short bullets.

This is an interesting point. For illustration, I looked at the usable case water capacity (capacity under the bullet) when I seated a long bullet (190 grain MatchKing) to the SAAMI max COL in a .30-06, .30-284, and .308 Win. The usable water capacities with the database default cases were 59.6, 53.7, and 46.3 grains, respectively, That puts the long bullet with the .30-284 at just 0.75 grains water capacity over half way between .308 and .30-06.

"First contemplation of the problems of Interior Ballistics gives the impression that they should yield rather easily to relatively simple methods of analysis. Further study shows the subject to be of almost unbelievable complexity." Homer Powley

Could you try that again, but for a .308 cal. 125 gr. spitzer? I got really good results from my Mark X 25-284, with 100 gr. bullets, so I never played around with my M-88 284, using anything lighter than the 150's. But I think you will see my "Spring Ahead", and not all of it is from the fat 284 Win.'s case body.
I never tried to go with the old classic Mauser 175 gr. round nose in my lever M-88. Thanx carpooler

With the flat base Sierra 125 grain SP #2120, the difference in usable case water capacity between .30-06 and .30-284 drops to about 2.2 grains with the bullet seated one caliber (0.308") into the case mouth. The usable space becomes 62.4 gr. and 60.2 gr. of water, respectively. The same bullet seated one caliber into a .308 case leaves only 50.2 grains of useable water capacity under it.

"First contemplation of the problems of Interior Ballistics gives the impression that they should yield rather easily to relatively simple methods of analysis. Further study shows the subject to be of almost unbelievable complexity." Homer Powley

I had those two rifles over thirty years ago. But your program pretty well shows my "Spring Ahead", And back in the day, I was using stick powders, with IMR on their boxes, exclusively. I'm left handed, and always in my right mind, but if I was one of those 'left lobe grinders', I'd look at a Rem 722, in 300 Sav.. It would be a real sleeper in 30-284. They had a one in twelve inch twist, that really shines with the lighter .308 bullets.

I had a .30-284 built from a Sako .308.
I sold it to a friend for no reason other than he wanted it real bad.
The only load I worked up for it was with the Hornady 165 gr boat tail,
CCI lr primer, 58.0 grains of IMR 4831. This load shot into one inch
at 2845 fps. Back off of .30-06 loads 10% and work up from there
watching for preasure signs. This round should give .30-06 performance
with bullets up to 180 gr. The long for weight bullets like Barnes and
Accubonds can get into the case too far and cut down powder capacity and
velocity potential. Good luck.